Naturalisation and citizenship in Singapore

Singapore welcomes skilled and economically active immigrants and gives citizenships easier than most other countries.
In general, the path to citizenship goes through a few years being PR (Permanent Resident), which in turn can be gotten after a few years living here on other residence visa.
The detailed requirements are unpublished and seem to keep changing. Ethnic background plays an important role: In general, Southeast Asian Chinese are preferred, followed by other Southeast Asians. Another factor is your economic contribution to Singapore: Working and earning well improves your chances, being housewife or retiree not.
Double or multiple citizenship is not allowed under any circumstance.
Becoming PR or citizen will make your sons liable for national (military) service, even if they are not Singapore citizen - you should seriously consider this before you apply!
The official criteria and procedures can be found on ICA's website.

What are the requirements for small business investment ? How a foreigner could get a retail business there

Foreigners can freely invest, start and own any business here.
Only if you also want to stay in Singapore and run that business yourself, do things get complicated.

beppi wrote:

Foreigners can freely invest, start and own any business here.
Only if you also want to stay in Singapore and run that business yourself, do things get complicated.

of course i want to to stay there & i have intentions to move there permanently ..what  complications arise ?

If you want to move to Singapore and run your own business, the visa you need is the EntrePass. The requirements are stated here:
    http://www.mom.gov.sg/passes-and-permit … ligibility
The criteria are applied very restrictively and it is NOT easy to get an EntrePass!

On citizenship, one thing is very clear that Govt always try to maintain the ratio starting from its independence in mid 60s that Singapore Chinese percentage should be around 71 to 72%, Singapore Malay should represents 11 to 12% and Singapore Indians would represents around 8 to 9% (mostly should be from Tamil ethnic groups). Same percentage applies on PR. ICA adjust this ratio each year so that it always maintains the balanced act. But, giving EP, S pass or work permit is completely depending on demand and supply in each sector. That’s why you do see there is no such balancing percentage e.g. nearly 18% Indians are EP holders, more than double to the percentage mentioned for citizens and PR (Indians get highest number of rejection while applying PR because EP & S pass holder Indians represent nearly 1/3 of all pass holders in this category more than double to its represents in PR n Citizens percentage). Same thing applies to people from Philippines who have 1% share in citizenship but in S pass category they are occupying more than 15%, 15 times higher than that ratio, so you will see they too get large number of PR rejection.

Now, it’s very difficult to get PR. I know people who got rejected are doctors, higher salaried professionals (monthly more than 15k, staying here more than 3 years). Because Govt always maintains that balancing act.